Such inductive torque sensor devices are generally considered known. They are, for example, being used in motor vehicles in order to determine torque values, such as steering torque. Such measures are becoming increasingly necessary, due to the fact that electromotive servos are being used as steering aids in more and more vehicles. These systems require a value for the steering torque in order to work. The steering torques are determined by a torsion bar inside the steering column using angular differences and calculated from this information. To this end, twists at the end of the torsion bar are converted to electronic signals using a suitable arrangement and fed into other devices for evaluation purposes. The angular differences caused by torsion are determined independently of the position of the steering wheel.
It is additionally important for driver assistance systems, such as ESP (electronic stability program used to influence the driving behavior of the vehicle), to receive information as to the positioning of the steering wheel (relative angular position). For this purpose, the lock of the steering wheel (angle relative to a reference position) is determined. To allow for angles greater or less than 360° to be determined, the reference position is associated with an indexing system, which generates a signal for every full revolution of the steering wheel and thereby determines the number of revolutions performed by the steering wheel. Other methods of determination are possible as well.
EP 1 932 221 B1 describes an electric motor equipped with a sensor to determine the positioning of a rotor, where the sensor is mounted on a connecting panel.